This is a classic example of the logical fallacy called Begging the Question
Originally Posted by Wikipedia:
Begging the question (Latin petitio principii, "assuming the initial point") is a type of informal fallacy in which a proposition relies on an implicit premise within itself to establish the truth of that same proposition. In other words, it is a statement that refers to its own assertion to prove the assertion. Such arguments are essentially of the form "A is true because A is true" though rarely is such an argument stated as such. Often the premise 'A' is only one of many premises that go into proving that 'A' is true as a conclusion.
The article invites you to presume that "Windows PC sales are down by 21%" (let's set-aside how that particular number was computed ...)
is somehow related to "Windows-8 (sucks)." (Which it un-arguably
does, but let's set-aside that, too. )
In fact there is no cause to assume that such a correlation holds.
The difficulty that is facing MIcrosoft right now is simply that the entire
market for computing is undergoing its next technological evolution: the devices that really matter are the ones that fit in your pocket. Even within "traditional" desktop/laptop bastions, people want even more immediate access to their information and they want it wherever they are now.
Furthermore, they want a specialized solution to their
most-immediate need; not a be-all/end-all thingamabob that requires an IT department just to understand it.
(Fair warning, Linux IT-infrastructure 733T D00DZ! This particular sea-change is aimed squarely at your job, too!)